1. Field of the Invention
The subject invention relates to a heat exchanger employing stamp formed sheets to define fittings between heat exchange tubes.
2. Description of the Prior Art
Heat exchangers are used in air conditioners, refrigerators and other such apparatus. A typical prior art heat exchanger includes an array of tubes for carrying a heat exchange fluid. Air is urged in proximity to the tubes to effect a heat exchange between the fluid in the tubes and air flowing past the tubes.
Space limitations of air conditioners, refrigerators and other such equipment requires a fairly compact array of tubes in the heat exchanger. A typical prior art heat exchanger is identified generally by the numeral 10 in FIG. 1. The prior art heat exchanger 10 includes a plurality of heat exchange tubes 12 of substantially equal length. The tubes 12 each have opposed ends 14 and 16 respectively. Thin metallic heat exchange fins 18 are mounted over the tubes 12 in substantially parallel relationship to one another and substantially orthogonally to the tubes 12. Although only three heat exchange fins 18 are depicted in FIG. 1, it is understood that the array of heat exchange fins 18 will extend substantially along the length of the respective tubes to facilitate the heat exchange process. Portions of the tubes 12 in proximity to the ends 14 and 16 are deformed to define annular beads 20 and 22 respectively at selected distances from the corresponding ends 14 and 16.
The prior art heat exchanger 10 further includes mounting plates 24 and 26. The mounting plates 24 and 26 are provided with apertures 28 and 30 which define diameters approximately equal to the diameters of the tubes 12, and smaller than the diameters defined by the respective annular beads 20 and 22. Thus, portions of tubes 12 in proximity to ends 14 are urged through apertures 28 in the mounting plate 24. Similarly, portions of the tubes 12 in proximity to the ends 16 are urged through the apertures 30 in the mounting plate 26. In this manner, the tubes can be maintained in substantially parallel relationship to one another with the ends 14 and 16 projecting selected distances from the mounting plates 24 and 26.
Assembly of the prior art heat exchanger 10 proceeds by mounting a solder ring 32 over the ends 14, 16 of tubes 12 projecting beyond the respective mounting plates 24, 26. Fittings 34, which extend through 180.degree., are then mounted to the respective ends 14, 16 of the tubes 12. The fittings 34 extend from one tube 12 to an adjacent tube, with the overall pattern of tube-to-fitting connections being selected to achieve a continuous flow of heat exchange fluid through all of the tubes 12 and fittings 34 of the prior art heat exchanger 10. The assembled heat exchanger is then heated sufficiently to cause the solder rings 32 to melt and wet into the region between the tubes 12 and the fittings 34 for achieving permanent connection therebetween.
Prior art heat exchangers 10 function well. However, the manufacturing process is labor intensive, time consuming and costly. In particular, the solder rings 32 must be mounted individually onto the tubes 12 by hand. Similarly, the fittings 34 extending between each of the respective tubes 12 must be manually urged into place. Improper mounting of either the solder rings 32 or the fittings 34 can result in leaks of the heat exchange fluid with corresponding negative consequences to the environment. Additionally, the heat applied to the entire apparatus may not be uniform, with the result that some solder may not completely melt or that certain portions of the heat exchanger 10 may be damaged by excessive heat.
In view of the above, it is an object of the subject invention to provide an improved heat exchanger.
It is a further object of the subject invention to provide a more efficient method of manufacturing a heat exchanger.